The subject of this invention is an adjustable depth magnetic device consisting of a switchable magnet, switchable magnet carrier, or switchable magnet integrated into a carrier (collectively “MagnaJig”) and a receiver, wherein the MagnaJig is constrained to a receiver. The adjustable depth magnetic device may be affixed to or integrated into an object to constrain said object to a ferrous target; alternatively, the adjustable depth magnetic device may be affixed to or integrated into a fixture to aid in manufacturing, production, and/or assembly operations.